#include <atcoder/segtree>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
const long long INF_LL = 2000000000000000000LL;
const int INF = 2000000000;
const long long MOD = 1000000007;
#define ll long long
#define all(x) x.begin(), x.end()
#define REP(i, a, b) for(int i = a; i < b; i++)
#define rep(i, n) REP(i, 0, n)
// typedef float double;
// typedef priority_queue prique;
typedef pair<int, int> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<P> vp;
typedef vector<ll> vl;
typedef vector<vi> matrix;
int dx[4] = {0, -1, 0, 1};
int dy[4] = {1, 0, -1, 0};
int sign[2] = {1, -1};
template <class T> bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}

ll modpow(ll a, ll b, ll m) {
    if(b == 0)
        return 1;
    ll t = modpow(a, b / 2, m);
    if(b & 1) {
        return (t * t % m) * a % m;
    } else {
        return t * t % m;
    }
}

struct edge {
    int to;
    ll cost;
    edge(int t, ll c) { to = t, cost = c; }
};

typedef vector<vector<edge>> graph;

// using mint = modint998244353;

P op1(P x, P y){
    if(x.first < y.first){
        if(x.second < y.first){
            return {x.first, x.second};
        }else{
            return {x.first, y.first};
        }
    }else{
        if(y.second < x.first){
            return {y.first, y.second};
        }else{
            return {y.first, x.first};
        }
    }
}
P e1(){return {INF, INF};}

int op2(int x, int y){return max(x, y);}
int e2(){return 0;}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int n;
    cin >> n;
    vi a(n);
    rep(i, n) cin >> a[i];
    segtree<P, op1, e1> seg1(n);
    segtree<int, op2, e2> seg2(a);
    ll ans = 0;
    rep(i, n){
        seg1.set(i, {a[i], INF});
    }
    rep(i, n){
        int l = i, r = n + 1;
        while(r - l > 1){
            int m = (l + r) / 2;
            P tmp = seg1.prod(i, m);
            if(tmp.first + tmp.second >= seg2.prod(i, m)){
                l = m;
            }else{
                r = m;
            }
        }
        ans += l - i - 1;
    }
    cout << ans << endl;
    return 0;
}